1. Field of the Invention
The invention relates to a surgical instrument for emergency medicine, in particular a so-called coniotomy device with a trocar, an indwelling cannula that can be inserted into the trachea and a collar affixed outside to the neck.
2. Description of Related Art
Coniotomy devices of this type are known to the art. The German Patent 88 85 715 C7, for instance, describes such a device, under which a collar to be positioned on the neck, with a flange inclined at an angle of less than 45 degrees to the collar surface, is equipped with a fastening component, into which an axially conducted catheter system with a cannula and stylet can be inserted and, after the successful introduction into the breathing tract, can be arrested by means of a clamp stop on the fastening component.
Moreover, U.S. Pat. No. 3,906,956 describes such an instrument that has an L-shaped configuration and an opening for a trocar.
Furthermore, U.S. Pat. No. 4,791,690 discloses a similar instrument that features a self-limiting depth penetration device, restricting penetration to the back third of the trachea, and has tube-shaped nozzles originating on both sides from an oval flange, allowing passage of an air tube to be inserted into the trachea.
Finally, similar instruments have become known from the two U.S. Pat. Nos. 3,476,112 and 2,923,299 and the German Patent 19 514 433.
It is evident that these known coniotomy devices have considerable disadvantages. Their structure is too complicated for use in emergencies, consisting as they do of too many individual parts to be assembled prior to use. Moreover, they are too difficult to manipulate even for an experienced physician in such situations, leading to the loss of valuable time that could possibly be decisive in saving the life of the patient. Instruments equipped with complicated mechanics and with cannulas inserted into the trachea in bent form can rarely be used in real-life situations; in particular, those with bent cannulas are totally inappropriate for emergency medicine.